More than 3,000 calves are being donated by farmers across the country to be auctioned off to benefit people with disabilities.
Scott and Lye Farm - on the outskirts of Hamilton have made it an annual competetion to rear the heaviest calf - and whoever wins shouts lunch.
Lye Farm haven't won the mini competition in three years but Farm Assistant Ashleigh Wenham says their calf is rather spoilt with meal, hay, and milk despite being more than four months old.
"Just because we're trying to get them as heavy as they can be. We want to beat them [Scott Farm]."
Both farms' reputations are on the line. But Tom Hoskins from Scott Farm says it's all in good gesture.
"We're not force feeding them, they're eating ad-lib pretty much so they're gonna gain weight in their own time."
Last year there were rumours of teams swapping calves between farms... and this year has not been a clean fight either.
"We've snuck over a few times and checked on their calves, and weighed them", Ms Wenham says.
For the first time in three years, the women at Lye Farm took home the honour - their calf's were 50 kgs heavier.
But Mr Hoskins believes this year it's rigged, but he's not worried because it was all for a good cause "giving back to the community".
In the last three decades more than $30 million dollars has been rasied for IHC.
Caroline Sinclair has helped raise Kristoff the calf on Lyes farm and says it's been great to be a part of it "because the money will go towards helping these people and get caregivers to help them as well and equipment and everything like that."
The calves from Scott and Lye Farms will be auctioned of this weekend at the Frankton Stockyard in Kent St.